Motor-governing device



PFLKJTION FILED MAY16|19`|9. 1,393,433. Patented Oct. 11, 1921.

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NVENTOR \N.W.DE N BWM ATTORNEY UNITE SFA'FEIS' essi" eveil-t5 Param ori-Ica WILLIAM W.:'DEAN, OF .WILMETTE, II.-L.l\TOIS, ASSIGNOR TO EFFICIENCY ELECTRIC CORPORATION, OF NEW YORK, N. Y., .A CORPORATION OF NEW YORK.

' Moron-Goverment@ DEVICE'.

- Be it known that I, WILLIAM vW'. DEAN, a citizen of the United States, residing at Wi1me'tte,'in''the "county" of Cook and State of Illinois,"'havefinvented certain new and useful lImp'roverneiit-s in Motor -Governing Devices; and I do hereby declare the following to-be''a full, clear, concise, and` exact descriptioiiof the invention, 'such as'will enable those/skilled inthe art to which it Yap-A pertain's to make anausethe-samev" Myinvention relates 4to f motor governing devices', xand more'V 'particularly to'devices which arek responsiyel to fthe'speed of an electric motor to control suchispee'd, j Y "1 -'More particularly my invention is especially adapted/"for: use'in 'connection with;

electric phonograph motors, and is adaptableto operate in connection with so calledV ,universa`l"motors which are capable of :operating interchangeably on' alternating type, and may in order to meet'the various and direct'c'uirent sources of` currentA supply.

v In v the Lpresent 'invention *I .Y disclose -a motor speed controlling system involvingthe very minimum` of the very simplest kind Aof positivelyoperating elements which isinexpensive 'to manufacture, easy Vto assemble, and when operated is capable of beingeasily adjusted'andadapted to rr'iaintainr such ad- Yjustment for long periods of time.

Other objects of my invention andthe invention' itself willbef'made clear by referspecification in which-'at Yence tothe drawings accompanying this phonograph electric motor.

In Fig'. 2,I .show a modification of the system of L 'involving the use of'a re- Y, lay and by ,virtue of this :relaythe energization of the 'motor is made variable, according to Athe :degree of speed corrections" required g* this"'control' of thenmotor energization being inv addition to the effect produced by the electrical 'brake' effect' which isl produced in'thestructure'illustrated in Fig.- l.

Referring to vFig. 1, at"A',-`Ishow asection of aphonograph lcabinet-,in which is mounted a phonograph electric'motor M, which may-be` of the series or'shunt wound cinditions of practice, be preferably' constructed of the vso called universal type which are capable' of operating 'with alternatingor direct currents.Y 'Y

i I show an embodiment of my, invention used .to control the v`speed of a .l .Specicationof Letters Patent.A Patented Oct 11, 1921.

' n ppneatipn'- inea Mayas, 1919. seriai No; 297,623.

A motor shaft S, for the motor, carries a alinement with the axisioflrotation'of the'l shaft S, and adapted to cooperate when the motor is operated with an opposing -electrical contact EC. The opposing contact EC is stationary,l and its position may be adjusted by means of an adjusting knob K, operating through a worin and gear mechanism Q; the arrangement being such that upon turning the knob K, the' Contact carryingrod R is rotated, land lby virtue of an eXternal'thre'ad 'I on the rod and a coperating internal thread IT in the supporting mount SM, the contactKEC upon such rotation of the rod is advanced, being withdrawn toward or from the reed contact CE. The disposition of thev reed spring "FR, is such thatit normally extends in a plane at an angle to the plane of rotation of the-shaft and the carried flywheel member F, and by centrifugal force its outer eXtermity is caused to be thrown outwardly, and the effective result is that the end of the reed member is deflected in a direction tending to bring the reed spring into alinement with the' aforesaid plane 'of rotation, and thus the contact CE upon increasing motor speeds is advanced outwardly on a direction away from the motor until when a predetermined speed is reached,^the reed carried contact CE engages the stationary contact EC. When this occurs, a circuit is completed extending in a bridge of the power circuit conductors lfand 2, Vthis circuit containing the serially connected governing contacts EC-CE, and an electromagnet winding EM.

The electromagnet Ywinding is carried on a' laminated iron'or steel core, which preferably I construct of silicon steel stampings as these are found to introduce very little eddy current'and hysteresis losses with a maximum of magnetic permeability at low magnetic densities.

I preferably make the electromagnet lOO winding EM, of a large number of turns of wire, so as to secure a suiiicient magnetic effect.' and the wire being ot' small diameter a relatively high resistance is interposed in the bridge circuit.

When the circuit is closed at the governing contacts, due to the high resistance of this circuit, its high impedance or both, the sparking at these governing contacts is made very small and since the spark is almost purely an inductive spark and due to an oscillatory inductive discharge when the contacts are broken, the spark can .be entirely subdued by a suitable bridging of these contacts by a condenser, or a high noninductive resistance; these expedients are well known in the art and are not herein illustrated, beingomitted for the sake of simplicity in disclosure.

Also in -bridge of the current supply conductors l and 2, I connect the terminals of the electric' motor M.

-The operation of the system of Fig. l, is as followsz-When a source of alternating ordirect current is connected to the incoming current leads 1 and 2, by operating an electric switch, not shown but understood, the motor will rotate its shaft S, at a speed depending upon the current supplied to the motor; The reed Spring magnet F R and its carried contact CE and the stationary contact EC are so disposed that at a predetermined motor speed, the contact CE engages the fixed contact'EC, whereupon the bridged circuit comprising these contacts and the serially connected electromagnet winding EM, is closed; and current from the current supply source will flow over this circuit, energizing the electromagnet and cause a flow of magnetic lines of force between the polar extremities of the magnetic circuit comprising the laminated magnetic core IC. Interposed in the path of these magnetic lines of force, is the rotating flywheel F, which rotates its near-peripheral portion between the magnetic poles of the electromagnet.

This sets up Foucault, or so called eddy currents in the disk-flywheel member, and which eddy currents in turn set up a magnetic field which cooperating with the pri mary magnetic field set up by the electromagnet in such a way that the primary eld lines of force and the secondary field lines of force, attract one another so that there is a retarding of the speed of the electric disk, due to a magnetic drag on the rotat ing copper flywheel. Therefore it is to be seen that whenever the electromagnet is energized, that the motor speed is retarded and this effect is instantaneous, so that very quick corrections of motor speed are to be had in the system of my invention wheneverl such motor speedweXceeds a predetermined high limit of motor speed.

tion is needed, and since this is yso the elec--v tromagnet of my invention takescare of this automatically, in that it also is less'etieient to retard the speedof the motor whenf operating with alternating currents than with direct currents. This fact coupled with the fact that the corrective effect'is-obtained instantaneously, enables me to use the same universal motor with a given adjustment for alternating or direct currents over aconsiderable' range of voltage of applied current, and I accomplish this result without undue sparking at the governing contacts, and at the same time secure a powerful braking action under the controlv of. these. contacts. .Y

Referring now more particularly to Fig. 2, I show at R, an electrical relay connected in a circuit in the same wav asthe jmagnet EM of Fig. l is connected in the circuit illustrated in Fic'. l.

The magnet EM of Fig. 2, however, is connected in a local circuit independent of the governing contact (EE-EQ the circuit for the magnet EM of Fig. 2, comprising. serially included normally open contacts'of the relay R. Serially included in the energizing circuit of the motor-M, is a resistance coil RC, normally shunted by normal contacts NC of the relay R.

By virtue of this arrangement when the governing contacts are closed and the relay R is operated, in addition to the braking effect of the electromagnet EM upon the iiywheel-disk F, a reduction in motor energization is had by the interposition of the serially included resistance coil RC in this energizing circuit. Thus, the braking effect upon the flywheel disk F, is magnified.

While I have illustrated .a specific embodiment of my invention for the purpose of illustrating the same, I do not wish to be limited to suchv an embodiment'as I-V am aware that numerous and-extensive departures may be made from that herein specilically illustrated and described, without departing from the spirit of my invention, but what I claimvis limited only by the defining appended claims l. In combination with van electric motor, of a set of speed responsive contacts associated therewith and adapted tooperateupon2 Y l 130 a predetermined motor speed, aV motor shaft,

an .armature disk rotatedjby the said shaft when the motor visioperated, a field electrovedge thereof,' said"magnet .adapted lwhen energized to retard'the speed fof-rotationv of the I said armature, said .speed-.responsive contacts whenl operated causing1 the energiz'ation'ofivthe'lsaidfield magnet.I

2. In' combination with an electric motor, of a' set ofelectrical contactsadapted to be fr rcsponsiveto complete a circuit at a prein the lsaid circuit; f:

' '-tated by the said shaft when the said motor is determined motor speed,'a motor shaft for thesaid motor,a thinrotatable armature disk of good current conducting material driven by the said shaft `and''a'.daptedito be rotated when the 'saidmotorsisfoperatei al pair of opposing eldnagnet` poles disposed on opposite sides of the'rotating disk and separated 4'from each f other a 1 distance only slightly exceeding thethicknessof thesaid armature disk and adapted-when 'energized to retard 1 the Ispeed 'of rotation lof' the Y said armature`,"a field magnet-:winding :and a source ofenergizingy current being. -included 'combination 'with a phonograph, of a 'turn-table' therefor, an electric motor for operating said turn-table, Aa source of `cur' rent-for energizingthejsaid motor, a thin metallicV lnon-magnetic i armature disk, ,ro-

operated, ia field magnet forsaid` armature disk adapted when :energized to project a stream of magnetic lines 4through the said disk to retard the speed of rotation of the said armature" disk, a winding for the said fieldv magnet adapted to =be energized by the said 'sourcef of current, centrifugally operated `meansjto cause'the energization of the said' magnet -upon' a predetermined motor1 speed, and to cause denergization thereof upon lower speeds.

4." In` combination with an electric motor, a source of current for energizing thesaid motor, a shaft adapted to be rotated by the said motor "When'the said motor is'energized a metallic vdisk of nonmagnetic material secured to the said shaft and adapted to be rotated thereby, an electromagnet comprising magnetic poles between Which the said dislris ladapted to revolve', an energizing Winding "for the said electromagnet, speed controlled contacts associated with the said motor and adapted, only When operated upon a predetermined motor speed, to associate the said source of current With the said energizing Winding.

5. In combination with an electric motor, a source of current for energizing the said motor, a shaft adapted to be rotated by the said motor when the said motor is energized, a metallic disk secured to the said shaft and adapted to be rotated thereby, an electromake an electrical connection with the said reed carried contact when the said reed is exedto a predetermined degree, said contacts being serially included in a circuit together vvith the said source of current and with the said energizing electromagnet Winding. Y

@6l In combination, an electric motor, a motor driven shaft, a thin disk of good electrical 'conducting material carried on ther said shaft and rotated thereby, an electromagnet having opposing poles disposedon either side of the disk near the same'edge thereof,fsaid poles being so disposed that the material of the disk Will comprise .a substantially large portion of the interpolarspace, and intercept the flo7 of magnetic iiux across the said space, a source offcurrent, a speed responsive member, a pair of. normally separated electric con tacts, an energizing circuit for the said electromagnet, said circuit including said contacts and said source of current, said contacts being adapted to be closed whenever a predetermined desired motor speed is exceeded under the control of said speed responsive member, said electromagnet When energized being adapted to set up considerable flows of Foucault currents in the said disk, the reaction of the said currents being edective to immediately exercise a considerable retarding effect on the said disk to reseparate the said contacts.

7. In combination, an electric motor, a motor driven shaft, a thin disk of good electrical conducting material .carried on the said shaft and rotated thereby, an electromagnet having opposing poles disposed on either side of the disk near the same edge thereof, said poles being so disposed that the material of the disk Will comprise a substantially large portion of the interpolar space, and intercept the flow of magnetic flux across the said space, a source of current, a'speed responsive member, a pair of normally separated electric contacts, an energizing circuit for the said electromagnet, said circuit including said contacts and said source of current, said contacts being adapted to be closed Whenever a predetermined desired motor speed is exceeded under the control of said speed responsive member, said electromagnet when energized being adapted to set up considerable liows of Foucault currents in the saidv disk, the reaction 0f the said currents being effective to im- Cri mediately exercise a considerable retarding effect on the said disk to re-separate the said contacts, a motor energizing circuit, a second pair of contacts, said contacts being normally closed and controlling the said motor energizing circuit, all of said contacts being operated at the same motor speed, and effective to reduce the motor speed.

8` In combination, an electric motor, a motor driven shaft, a thin disk of good electrical conducting material carried on the said shaft and rotated thereby, an electromagnet having opposing poles -disposed on either side of the disk near the same edge thereof, said poles being so disposed that the material of the disk will comprise a substantially large portion of the interpolar space, and intercept the flow of magnetic flux across the said space, a source of current, a speed responsive member, a pair of normally separated electric contacts, an energizing circuit for the said electromagnet, said circuit including said contacts and said source of current, said contacts being adapted to be closed Whenever a predetermined desired motor speed is exceeded under the control oi said speed responsive member, said electromagnet when energized being adapted to set up considerable flows of Foucault currents in the said disk, the reaction ot the said currents being effective to immediatel exercise a considerable retardino` eiiect on the said disk to re-separate the said contacts, said contacts being adapted to be restored on very slight speed retardations to instantly7 disable the speed retarding action of the said electromagnet.

9. In combination, an electric motor, a motor driven shaft, a thin disk of good electrical conducting material carried on the said shaft and rotated thereby, an electromagnet having opposing poles disposed on either side of the disk near the same edge thereof, said poles being so disposed that the material of the disk Will comprise a substantially large portion of the interpolar space, and intercept the flow of magnetic flux across the said space, a source of current, a speed responsive member, a pair of normally separated electric contacts, an energizing circuit for the said electromagnet, said circuit including said contacts and said source of current, said contacts being adapted to be closed whenever a predetermined desired motor speed is exceeded under the control of said speed responsive member,

said electromagnet when energized being said contacts, a motor energizing circuit, a

second pair of contacts controlling the said motor energizing circuit, all of said contacts being operated at thefsame motor speed and effective to reduce the motor speed.

l0. In combination, an electric motor,y a motor driven shaft, a thin disk of good electrical conducting material carried on the said shaft and rotated thereby, an electromagnet havingopposing poles disposed on either side of the disk near the same edge thereof, said polesbeing so disposed that the material of the disk will comprise a substantially large portion of the interpolar space, and intercept the flow of magnetic iux across the said space, a source of current, a speed responsive member, a pair of normally separated electric contacts, an energizing circuit for the said electromagnet, said circuit including said contacts and said source of current, said contacts being adapted to be closed Whenever a predetermined desired motor speed is exceeded under the control of said speed responsive member, said electromagnet when energized being adapted to'set up considerable flows of Foucault currents in the said disk, the reaction of the said currents being effective to immediately exercise a considerable retarding eiect on the said disk to re-separate the said contacts, a motor energizing circuit, a

second pair Aof contacts controlling the said motor energizing circuit, all of said contacts being operated at the same motor speed and effective to reduce the motor speed, said contacts being adapted to be restored on very slight speed retardations to instantly disable the speed' retarding action of the said electromagnet.

In witness whereof, I hereunto subscribe my name this 14 day of May, A. D. 1919.

vWILLIAM W'. DEAN. 

